SC4524EVB

Programmable Frequency, 2A Output 30V Step-Down Switching Regulator POWER MANAGEMENT Description The SC4524 is an adjustable frequency peak currentmode step-down switching regulator with an integrated 2.3A, 30V switch. The SC4524 can be programmed up to 1.5MHz. This allows the use of small inductor and ceramic capacitors, resulting in very compact power supplies. The SC4524 is suitable for next generation XDSL modems, set-top boxes and point of load applications. SC4524 Features u u u u Up to 1.5 MHz Programmable Switching Frequency 2.3A Integrated Switch Wide Input Voltage Range 2.8V to 30V Peak Current-Mode Control with Cycle-by-Cycle Current Limiting Hiccup Overload Protection Soft-Start and Enable Thermal Shutdown Thermally Enhanced 8-Pin SOIC Package Fully WEEE and RoHS Compliant u u u The SC4524 uses peak current-mode PWM control for ease of compensation. Cycle-by-cycle current limit and u hiccup overload protection reduce power dissipation u during overload. Combined soft start and enable pin not only eliminates output start up overshoot but also allows power sequencing. The SC4524 is available in SOIC-8 EDP package. Applications u u u u u u XDSL and Cable Modems Set-top Boxes Point of Load Applications CPE Equipment DSP Power Supplies Disk Drives Typical Application Circuit Efficiency 90 V IN 2 4V 85 IN D1 SS C7 2 2nF BST Efficiency (%) C2 1 N4148 0 .1 mF L1 80 OUT 5 V/2A R1 2 2.1k SC4524 COMP SW 75 70 65 60 55 4 .7 mH FB C6 2 2pF R5 1 5.4k C5 4 70pF ROSC R3 1 7.4k GND C3 1 0 mF D2 2 0BQ030 C1 2 2 mF R2 5 .49k L 1: Coiltronics FP3-4R7 C1: Murata GRM21BR60J226M C3: Murata GRM32ER71H106K 50 0.0 0.5 1.0 1.5 2.0 Load Current (A) Figure 1. 1MHz 24V to 5V/2A Step-down Converter. Revision: December 30th, 2006 1 www.semtech.com SC4524 POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Parameter Input Voltage BST Pin BST Pin Above SW SS Pin FB Pin SW Voltage SW Transient Spikes (